AB0624 Patients with vasculitis have a high prevalence of coronary microvascular dysfunction
Authors: Z. Wallace, B. Weber, S. Parks, C. Cook, D. Huck, J. Brown, S. Divakaran, J. Hainer, C. Bibbo, V. Taqueti, S. Dorbala, R. Blankenstein, K. Liao, A. Aghayev, H. Choi, M. Di Carli
Journal: Annals of the Rheumatic Diseases (2022)

Background Vasculitides are a heterogenous group of diseases characterized by intense vessel wall inflammation, endothelial injury, and systemic inflammation. Several vasculitides are associated with high risk of cardiovascular (CV) disease, an important source of morbidity and mortality in this population. This excess CV risk is attributed both to a high burden of traditional risk factors and to inflammation, but this remains poorly studied. Indeed, inflammation is a known risk factor for CV disease and implicated in coronary microvascular dysfunction (CMD) which may precede obstructive coronary artery disease (CAD). Objectives We sought to assess whether vasculitis is associated with CMD in the absence of obstructive CAD. Methods We retrospectively identified subjects with systemic vasculitis who underwent symptom prompted rest/stress myocardial perfusion PET. Patients with an abnormal myocardial perfusion study (summed stress score ≥3) or LVEF&lt;40% were excluded. Controls were identified from the same population and matched on age, gender and cardiovascular risk factors (CAD, hypertension, dyslipidemia, diabetes mellitus, and obesity). Coronary flow reserve (CFR), was calculated as the ratio of myocardial blood flow (ml/min/g) at peak stress compared to rest. CMD was defined as CFR &lt;2. Results We studied 26 vasculitis cases and 66 matched controls. The most common vasculitides were giant cell arteritis (38%), ANCA-associated vasculitis (31%), and Takayasu’s arteritis (12%). Median (IQR) time between diagnosis and PET was 6.5 (2.9, 14.2) years. Seven (27%) cases had active vascultis at the time of PET. Cases and controls were well-matched on age, sex, and CV risk factors (Table 1). Despite a similar prevalence of CV risk factors, coronary flow reserve (reflected by CMD) was abnormal in 38% of vasculitis cases compared to 15% of controls (p=0.004). The mean [SD] CFR was 19% lower in vasculitis cases vs controls (2.11 [0.5] versus 2.6 [0.7], p=0.003). Table 1. The presence of coronary microvasculature dysfunction in patients with systemic vasculitis without obstructive coronary artery disease Cohort characteristics Vasculitis (n=26 ) Control (n=66 ) P-value Age at PET, years 62 (18) 61 (17) 0.24 Time from Vasculitis Diagnosis to PET, years (median, IQR) 6.5 (2.9, 14.2) n/a Female, n (%) 18 (72%) 43 (65%) 0.99 Vasculitis Characteristics Large Vessel (e.g., giant cell arteritis, Takayasu’s), n(%) 13 (50%) n/a n/a Medium Vessel (e.g., polyarteritis nodosa, Kawasaki’s arteritis), n(%) 2 (8%) n/a n/a Small Vessel (e.g., ANCA-associated vasculitis, Henoch-Schonlein Purpura), n(%) 11 (42%) n/a n/a Cardiovascular Risk Factors At Diagnosis At PET At PET Hypertension, n (%) 12 (46%) 20 (71%) 47 (80%) 0.47 Obesity, n (%) 3 (12%) 2 (32%) 2 (32%) 0.84 Diabetes, n (%) 3 (12%) 5 (20%) 13 (20%) 0.99 Dyslipidemia, n (%) 4 (15%) 15 (58%) 40 (61%) 0.99 Known CAD, n (%) 0 (0%) 1 (4%) 1 (2%) 0.48 Imaging Findings Rest myocardial blood flow, ml/min/g 1.0 (0.3) 1.0 (0.3) 0.8 Stress myocardial blood flow, ml/min/g 2.1 (0.6) 2.6 (1.0) 0.008 Coronary Flow Reserve, ml/min/g* 2.1 (0.5) 2.6 (0.7) 0.003 Coronary Microvasculature Dysfunction** (CMD), n (%) 10 (38%) 11 (15%) 0.004 Conclusion Patients with systemic vasculitis, even in the absence of obstructive CAD, have a high prevalence of CMD compared with non-vasculitis patients. These differences were observed despite matching cases and controls on traditional CV risk factors, highlighting the importance of other factors, such as inflammation and vasculitis treatments on CMD and CV disease in this population. CMD is a known independent risk factor for CV mortality. Future prospective studies are needed to understand the relationship between vasculitis, systemic inflammation, and CMD. Disclosure of Interests None declared